Trackball for computer system monitor



FIG. 1 is a top front and side perspective view of a trackball for computer system showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a front elevational view thereof; and,

FIGS. 6 and 7 are, respectively, right and left side elevational views thereof. 

The ornamental design for a trackball for computer system monitor, as shown and described. 